1. Field of the Invention
The present invention relates to a magnetic resonance imaging apparatus which can help silence operation noise by enclosing noise sources associated with its gradient magnetic field coil.
2. Description of the Related Art
There has been known a magnetic resonance imaging apparatus in which vacuum is created around the gradient coil in order to reduce the noise caused by the vibration of the gradient coil for silencing the apparatus, as discussed in Jpn. Pat. Appln. KOKAI Publication No. 10-118043.
The magnetic resonance imaging apparatus disclosed in Jpn. Pat. Appln. KOKAI Publication No. 10-118043 has such a structure that spaces created between cylindrical bore tubes and static field magnets are encapsulated by sealing covers fixed to side ends of the bore tubes and side ends of the static field magnets.
With the above-described conventional structure, the air pressure applied to the sealing covers is received by the static field magnets and the bore tubes. Therefore, the bore tubes and the sealing cover are tightly coupled, thus making it difficult to achieve an anti-vibration structure. Further, with this structure, the air pressure acts as a buckling force on the bore tubes. Therefore, it is necessary to increase the rigidity of the bore tubes and therefore it is difficult to reduce the thickness of the bore tubes.